Safety appliance for elevators.



J. T. HALL.

SAFETY APPLIANCE FOR ELEVATORS.

APPLICATION FILED APR.28,1915.

1 21234? Patented Jan.16,1917.

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Patented Jan. 16, 1917.

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. TINTTED STATES PATENT @FFTQE.

JAMES '1. HALL, OF COALINGA, CALIFORNIA. ASSIGNOR 0F ONE-THIRD TO BUN TING IRON WORKS, OF COALINGA, CALIFORNIA, A CORPORATION OF CALIFORNIA, AND ONE-THIRD TO G. T. MOUNTFORD, OF COALINGA, CALIFORNIA.

SAFETY APPLIANCE FOR ELEVATORS.

Application filed April 28, 1915.

T 0 all whom it may concern:

Be it known that I, JAMES T. HALL, a citizen of the United States, residing at Coalinga, in the county of Fresno and State of California, have invented certain new and useful Improvements in Safety Appliances for Elevators, of which the following is a specification.

The hereinafer described invention while applicable for use in connection with elevators generally, mine hoists and similar devices for raising and lowering bodies and wherein the falling or dropping of the moving member for an appreciable extent is to be provided against in case of a rupture of its supporting means, is more particularly designed for use in connection with passenger elevators employed in oiiice and other buildings.

The object of the invention is to provide means carried by the movable member or elevator cage which automatically is thrown into action for frictionally engaging the fixed member of the elevator structure on a rupture or breakage of the cable or elevator support, and which by its frictional engagement with the fixed member of the elevator structure will positively and securely lock the movable member within the elevator well before the same falls or drops to an appreciable extent, thus protecting the passengers against serious injury and the loss of life occasioned by the failure of the safety means at present employed to properly lock the cage on a breakage of the supporting cable or cable utilized for raising and lowering the said elevator cage. l

The present safety appliance comprises a plurality of pressure actuated devices which, on a rupture or breakage of the hoist cable for the elevator, are automatically thrown into locking action due to the differences in the pressure of falling bodies to frictionally engage the fixed member of the elevator structure and lock the movable member thereto before the same falls or drops to an appreciable extent within the elevator well or shaft, the released movable member being thus gradually brought to a state of rest before appreciable momentum is attained and positively locked to the fixed member without injury thereto or to the passengers therein.

To comprehend the invention reference Specification of Letters Patent.

Patented J an. 16, 3191?.

Serial No. 24,464.

should be had to the accompanying sheets of drawings, wherein Figure 1 is a perspective view of an ordinary passenger elevator cage or movable member with the'safety appliance attached thereto for frictionally looking with the fixed member or elevator structure. Fig. 2 is a broken part sectional side elevation taken on the irregular line acw of Fig. 5 of the drawings. Fig. 3 is a perspective View of the elevator cage frame with the safety appliance applied thereto. Fig. a is an enlarged longitudinal sectional view taken on line g y of Fig. 5 of the drawings. F ig. 5 is an enlarged detail broken part sectional front elevation illustrating one of the safety appliances applied to the side frame pieces of the elevator cage and positioned for engagement with the cage guide of the elevator shaft.

In the drawings, the numeral 1 designates any suitable form-of an elevator cage, which in the present case is provided with the vertical side frame pieces composed of spaced angle posts 2-2 united at their tops and bottoms respectively by the longitudinally extended channel beams 3 and 3'. The parts 2 2 and 33 herein constitute an outer inclosing frame structure for the elevator cage, but it is obvious that any suitable form of constructed cage may be employed in carrying out the invention. For convenience, the elevator cage hereinafter shall be referred to as the movable member of the elevatorstructure, and the vertically disposed guides 4, which are secured to the inner walls and extend the entire height of the elevator well and which are provided with the outwardly projecting central web 4:, shall be referred to as the fixed member of the elevator structure. For all intents and purposes the parts 4 may be considered and treated as wall members of the elevator well within which operates the movable member 1 of the elevator structure.

In the present case, a plurality of the safety appliances are employed at each side portion of the elevator cage for frictionally looking with the fixed member of the elevator structure, but, inasmuch as the same are duplicates, the description of one will answer for the others.

For strengthening the angle posts 22' and preventing the spreading thereof, the

same are held together intermediate of their length and at the point where the safety device is applied by means of the clamp plate 5, which is secured thereto in any suit able manner. Within or between the angle posts 2-2 is located an open frame block 6, which is bolted to the said posts to move therewith with the lowering and raising of the movable member of the elevator structure. The said frame block is provided in its inner or back wall 7 with a vertically slotted portion 7 to receive the central web a of the guide a, and is partly closed at its upperend by the overhang sections 8. The said open frame block is provided with an interior chamber 9, formed with upwardly inclined inner wall surfaces 10. The said chamber 9 when the frame block 6 is properly positioned relative to the elevator structure is .subdivided vertically by the outwardly extended web a of the guides 4, which web projects therein through the slotted section 7,Fig. a of the drawings, and the said chamber 9 is closed at its bottom by the stirrup plate 11 secured to the lower end of the frame block 6 in any suitable manner. The front wall 12 of the open frame 6 does not extend downwardly the full length of the said frame, so the interior chamber 9 is left partly open at the front of the frame and this open portion is closed by the face plate 13 removably attached to the. frame block and the stirrup plate 11, the purpose of which face plate is to permit access to be had to the interior chamber 9.

From the stirrup plate 11 depends the open bracket 14, which in conjunction with the said plate 11 acts as a guide for the parallel vertically disposed spaced rods 1515, each of which at its upper end carries a head 16 provided with depressed cupshaped seat 17. These rods which serve and shall hereinafter be referred to as plungers work through guide openings 18 and 18 formed respectively in the bottom of the stirrup plate 11 and the open bracket 14 and the said plungers are held in their adjusted position by the tension of the springs 19, which springs surround the plungers and are interposed between the heads 16 thereof and the bottom of the stirrup 11. The pressure of these springs is counterbalanced by means of the adjusting weights 20 secured to the lower end portion of the rods or plungers 15 and 15 pro ecting below the stirrup plate 11, the weights resting on the collars 21 and being held to-' gether by means of the set collars 22. The said rods 15 and 15 are connected one to the other by means of plates 23, so as to insure the rods moving vertically in unison.

WVithin the chamber 9 are placed the friction balls 24: 'which are supported by the plungers 15 and 15 and rest within the seats '17 in the red heads 16, the balls-being thus held in spaced relation and at each side of the web 4. when the safety appliance is attached to the elevator structure. The springs 19 compensate for the weight of the balls 2% and of the plungers 15 and 15 and their associated parts, and hold the same in floating condition, rendering the same exceedingly sensitive and responsive to any change in pressures, and the pressure tension of the springs may be varied by increasing or decreasing the weights 20 to lower or raise the plungers 15 and 15 relative to the frame block 6. However, the proper position of the plungers 15 and 15' is obtained when the position of the balls 24 within the chamber 9 of the frame block 6 is such as to be free of contact with the inclined wall surfaces 10 of the chamber 9 and the side wall surfaces of the web 4:.

It will be understood that one of the described safety appliances is applied at each side of the elevator cage, although in the present case a plurality of said appliances is illustrated as applied to each side thereof.

The described safety appliance when applied to an elevator structure ascends and descends within the el vator well with the movements of the elevator cage. So long as the hoisting cable 25 for the cage is intact for effective working, the safety appliances remain inactive. However, should a rupture of the hoisting cable take place during the operation of the elevator, the cage suddenly drops within the elevator well. which dropping action destroys the equilibrium of the safety appliance and owing to the differences in pressures of falling bodies the friction balls 24 are quickly raised by the springs or lifted within the chamber 9 until they come into frictional engagement with the inclined wall surfaces 10 and the wall surfaces of the web 4: and by so doing gradually bring the movable member of the elevator structure, that is the cage, to a positive state of rest before appreciable momentum has been gained, due to the fact that the bearing surface of'the friction balls is gradually increased as the same move upwardly within the chamber 9 of the frame block 6.

The springs 19 may be eliminated without afiecting the working of the friction balls, but preference is given to the employment thereof for rendering the action of the frictionballs more sensitive than they would otherwise be.

By the use of the described safety appliance, the owners of buildings employing passenger and freight elevators are protected against damages for injuries which usually result on a breakage of the hoisting cable for the elevator cage. 7

I am aware that various changes may be made in the details of construction of the herein'describe'd safety appliances without creating a departure from the scope of the invention and equally so that the position of the safety appliance relative to the movable member of the elevator structure may be varied as desired, and I do not wish to be understood as limiting the invention to the herein described details of construction, but, on the contrary, wish to be understood as claiming for the invention as broadly as the state of the art will permit the application to elevator structures of automatically operated pressure actuated frictional means for looking a falling movable member to a fixed member within which it moves, the said means being thrown into locking action due to the differences in pressures of falling bodies, on a rupture of the supporting means for the movable member.

Having thus described the invention what is claimed as new and desired to be pro tected by Letters Patent is An elevator safety appliance for locking an elevator car against falling relative to the fixed guides between which it operates, the same comprising a pair of open blocks Copies of this patent may be obtained for one carried at each side of the car and each provided with a vertically disposed interior chamber increasing in width toward the lower end thereof and adapted to receive the webs of the guides, friction engaging balls in said chamber and positioned one at each side of said guide web, floating plungers supporting said friction balls and for forcing the same toward the shallow end of said chamber, springs for supporting said plungers and balls carried thereby and adapted for actuating said plungers to move said balls into locked engagement with the guide webs on a rupture of the supporting means for the car, and weights carried by said plungers for maintaining said plungers, balls and springs in a condition of unstable equilibrium.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JAMES T. HALL.

Witnesses:

HARRY H. To'rTEN, D. B. RICHARDS.

five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

